Pandemic Influenza

What is pandemic flu?
Pandemic flu occurs when a new flu virus rapidly spreads from country to country around the world, causing a global outbreak of serious respiratory illness that spreads easily from person to person. The swift spread of a pandemic flu happens because people are not immune to the new flu virus, and an effective vaccine would take months to develop. Depending on the nature of the virus, many people could become seriously ill and many people could die. Pandemics are not seasonal. A flu pandemic can happen at any time of year. By contrast, seasonal flu is the usual flu that occurs in the late fall, winter, and early spring.

Is pandemic flu likely to happen soon?
Although there currently is no pandemic flu in the world, many scientists believe it is just a matter of time until the next pandemic flu occurs. However, the timing and severity of the next pandemic cannot be predicted. Influenza pandemics occurred three times in the past century – in 1918, 1957-58, and 1968-69. There was significant concern that recent H1N1 influenza outbreak could develop into a pandemic, and there is continued concern that the bird flu known as H5N1, could develop into a pandemic.

What are the characteristics of a flu pandemic?
Influenza pandemics can rapidly spread throughout the world. Once international spread begins, a pandemic will be challenging to control because it is caused by a virus that spreads very rapidly by coughing or sneezing and that no one will be immune to initially. Infected people can transmit the virus before symptoms appear, adding risk that travelers without symptoms will spread the virus internationally.

The severity of disease and the number of deaths caused by a pandemic flu virus vary greatly, and cannot be known before the virus emerges. During past pandemics, infection rates reached 25 to 35 percent of the total population. The severe 1918 pandemic killed at least 40 million people worldwide.

Pandemics can cause large surges in the numbers of people requiring or seeking medical or hospital treatment, at times overwhelming health services. High rates of worker absenteeism can also temporarily interrupt other essential services, such as law enforcement, transportation, utilities, and communications. Although illness rates could peak quite rapidly within a given community, a second wave of global spread should be anticipated within a few months.

How would pandemic flu affect communities and businesses?
If an influenza pandemic occurs, many people could become sick at the same time and would be unable to go to work. Many others would choose to stay at home to care for sick family members. Schools and businesses might be closed to limit the spread of disease. Large group gatherings might be canceled. Public transportation might be scarce.

These are some of the challenges that local communities, schools, civic organizations, and businesses will face. They will need to work together to plan for a pandemic flu response. To minimize potential economic impacts, local governments are working with businesses and community leaders to develop plans to keep businesses operating when large numbers of employees are sick. To prevent employees from exposing themselves to disease, businesses are being asked to consider such measures as telecommuting, telephone-conferencing, and encouraging employees to stay home when sick.

What is being done locally to prepare for pandemic flu?
Although there is no pandemic flu at this time, public health officials are currently preparing for the possibility that a pandemic could occur in the future. This includes working with community partners to educate people about pandemic flu and the current situation.

Local public health officials are working with hospitals, emergency management, government officials, first responders, schools, businesses and many others to put together response plans. To prepare for any worst-case scenario, our plans include the possibility of large numbers of persons who could become ill and for large numbers of possible deaths. This planning includes how we will triage ill persons into hospital care, out of hospital care, and home self-care.

We are planning for how we are going to distribute a vaccine if one is available and how we would distribute anti-viral medication if there were an effective medication for the particular pandemic flu. And we are planning educational campaigns to keep people informed and make sure they know what they can do to protect themselves and others.

Vaccines and antivirals

What is the difference between a vaccine and an antiviral?
Vaccines are usually given as a preventive measure and are usually made from killed or weakened versions of the live virus to stimulate an immune response to the virus. Antivirals are drugs that may be given to help prevent viral infections or to treat people who have been infected by a virus. When given to treat infected people, antiviral medications may help limit the impact of some symptoms and reduce the potential for serious complications, especially for people who are in high risk groups. It is unlikely that antivirals would effectively contain the spread of an influenza pandemic or modify its course.

Is there a vaccine to protect people from pandemic flu?
Currently, there is no vaccine to protect people from pandemic flu. A vaccine probably would not be available in the early stages of a pandemic. Once a potential pandemic strain of influenza is identified, it will take several months before a vaccine will be widely available.

How will vaccine be distributed if a pandemic breaks out?
Most likely, the federal government will work with manufacturers, distributors, and states. States will develop distribution plans at the local level. The Health Department has identified a number of sites that would serve as mass dispensing clinics to distribute vaccine if it is available. The public would learn about these distribution sites through public health Web sites, the media, and other communication channels.

Fairness in vaccine distribution and use during a pandemic is important. Protecting people at high risk and protecting essential day-to-day services are also important considerations. Depending on availability, vaccine distribution might have to be prioritized according to such considerations as who responds to the emergency or has direct contact with the disease.

What other strategies will help protect people?
In the event of a pandemic, certain public health measures may be important to help contain or limit the spread of infection as effectively as possible. The following actions could include: